/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Cimarron D. Taylor of the University of California, Berkeley.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "posix-wasm.h"
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/mount.h>

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fnmatch.h>
#include <fts.h>
#include <grp.h>
#include <limits.h>
#include <pwd.h>
#include <regex.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>

#include "find.h"

static PLAN *palloc(OPTION *);
static long long find_parsenum(PLAN *, const char *, char *, char *);
static long long find_parsetime(PLAN *, const char *, char *);
static char *nextarg(OPTION *, char ***);

extern char **environ;

static PLAN *lastexecplus = NULL;

#define COMPARE(a, b)                   \
  do {                                  \
    switch (plan->flags & F_ELG_MASK) { \
      case F_EQUAL:                     \
        return (a == b);                \
      case F_LESSTHAN:                  \
        return (a < b);                 \
      case F_GREATER:                   \
        return (a > b);                 \
      default:                          \
        abort();                        \
    }                                   \
  } while (0)

static PLAN *palloc(OPTION *option) {
  PLAN *new;

  if ((new = malloc(sizeof(PLAN))) == NULL) err(1, NULL);
  new->execute = option->execute;
  new->flags = option->flags;
  new->next = NULL;
  return new;
}

/*
 * find_parsenum --
 *	Parse a string of the form [+-]# and return the value.
 */
static long long find_parsenum(PLAN *plan, const char *option, char *vp,
                               char *endch) {
  long long value;
  char *endchar, *str; /* Pointer to character ending conversion. */

  /* Determine comparison from leading + or -. */
  str = vp;
  switch (*str) {
    case '+':
      ++str;
      plan->flags |= F_GREATER;
      break;
    case '-':
      ++str;
      plan->flags |= F_LESSTHAN;
      break;
    default:
      plan->flags |= F_EQUAL;
      break;
  }

  /*
   * Convert the string with strtoq().  Note, if strtoq() returns zero
   * and endchar points to the beginning of the string we know we have
   * a syntax error.
   */
  value = strtoq(str, &endchar, 10);
  if (value == 0 && endchar == str)
    errx(1, "%s: %s: illegal numeric value", option, vp);
  if (endchar[0] && endch == NULL)
    errx(1, "%s: %s: illegal trailing character", option, vp);
  if (endch) *endch = endchar[0];
  return value;
}

/*
 * find_parsetime --
 *	Parse a string of the form [+-]([0-9]+[smhdw]?)+ and return the value.
 */
static long long find_parsetime(PLAN *plan, const char *option, char *vp) {
  long long secs, value;
  char *str, *unit; /* Pointer to character ending conversion. */

  /* Determine comparison from leading + or -. */
  str = vp;
  switch (*str) {
    case '+':
      ++str;
      plan->flags |= F_GREATER;
      break;
    case '-':
      ++str;
      plan->flags |= F_LESSTHAN;
      break;
    default:
      plan->flags |= F_EQUAL;
      break;
  }

  value = strtoq(str, &unit, 10);
  if (value == 0 && unit == str) {
    errx(1, "%s: %s: illegal time value", option, vp);
    /* NOTREACHED */
  }
  if (*unit == '\0') return value;

  /* Units syntax. */
  secs = 0;
  for (;;) {
    switch (*unit) {
      case 's': /* seconds */
        secs += value;
        break;
      case 'm': /* minutes */
        secs += value * 60;
        break;
      case 'h': /* hours */
        secs += value * 3600;
        break;
      case 'd': /* days */
        secs += value * 86400;
        break;
      case 'w': /* weeks */
        secs += value * 604800;
        break;
      default:
        errx(1, "%s: %s: bad unit '%c'", option, vp, *unit);
        /* NOTREACHED */
    }
    str = unit + 1;
    if (*str == '\0') /* EOS */
      break;
    value = strtoq(str, &unit, 10);
    if (value == 0 && unit == str) {
      errx(1, "%s: %s: illegal time value", option, vp);
      /* NOTREACHED */
    }
    if (*unit == '\0') {
      errx(1, "%s: %s: missing trailing unit", option, vp);
      /* NOTREACHED */
    }
  }
  plan->flags |= F_EXACTTIME;
  return secs;
}

/*
 * nextarg --
 *	Check that another argument still exists, return a pointer to it,
 *	and increment the argument vector pointer.
 */
static char *nextarg(OPTION *option, char ***argvp) {
  char *arg;

  if ((arg = **argvp) == NULL)
    errx(1, "%s: requires additional arguments", option->name);
  (*argvp)++;
  return arg;
} /* nextarg() */

/*
 * The value of n for the inode times (atime, birthtime, ctime, mtime) is a
 * range, i.e. n matches from (n - 1) to n 24 hour periods.  This interacts
 * with -n, such that "-mtime -1" would be less than 0 days, which isn't what
 * the user wanted.  Correct so that -1 is "less than 1".
 */
#define TIME_CORRECT(p) \
  if (((p)->flags & F_ELG_MASK) == F_LESSTHAN) ++((p)->t_data.tv_sec);

/*
 * -[acm]min n functions --
 *
 *    True if the difference between the
 *		file access time (-amin)
 *		file birth time (-Bmin)
 *		last change of file status information (-cmin)
 *		file modification time (-mmin)
 *    and the current time is n min periods.
 */
int f_Xmin(PLAN *plan, FTSENT *entry) {
  if (plan->flags & F_TIME_C) {
    COMPARE((now - entry->fts_statp->st_ctime + 60 - 1) / 60,
            plan->t_data.tv_sec);
  } else if (plan->flags & F_TIME_A) {
    COMPARE((now - entry->fts_statp->st_atime + 60 - 1) / 60,
            plan->t_data.tv_sec);
#if HAVE_STRUCT_STAT_ST_BIRTHTIME
  } else if (plan->flags & F_TIME_B) {
    COMPARE((now - entry->fts_statp->st_birthtime + 60 - 1) / 60,
            plan->t_data.tv_sec);
#endif
  } else {
    COMPARE((now - entry->fts_statp->st_mtime + 60 - 1) / 60,
            plan->t_data.tv_sec);
  }
}

PLAN *c_Xmin(OPTION *option, char ***argvp) {
  char *nmins;
  PLAN *new;

  nmins = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  new->t_data.tv_sec = find_parsenum(new, option->name, nmins, NULL);
  new->t_data.tv_nsec = 0;
  TIME_CORRECT(new);
  return new;
}

/*
 * -[acm]time n functions --
 *
 *	True if the difference between the
 *		file access time (-atime)
 *		file birth time (-Btime)
 *		last change of file status information (-ctime)
 *		file modification time (-mtime)
 *	and the current time is n 24 hour periods.
 */

int f_Xtime(PLAN *plan, FTSENT *entry) {
  time_t xtime;

  if (plan->flags & F_TIME_A) xtime = entry->fts_statp->st_atime;
#if HAVE_STRUCT_STAT_ST_BIRTHTIME
  else if (plan->flags & F_TIME_B)
    xtime = entry->fts_statp->st_birthtime;
#endif
  else if (plan->flags & F_TIME_C)
    xtime = entry->fts_statp->st_ctime;
  else
    xtime = entry->fts_statp->st_mtime;

  if (plan->flags & F_EXACTTIME)
    COMPARE(now - xtime, plan->t_data.tv_sec);
  else
    COMPARE((now - xtime + 86400 - 1) / 86400, plan->t_data.tv_sec);
}

PLAN *c_Xtime(OPTION *option, char ***argvp) {
  char *value;
  PLAN *new;

  value = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  new->t_data.tv_sec = find_parsetime(new, option->name, value);
  new->t_data.tv_nsec = 0;
  if (!(new->flags &F_EXACTTIME)) TIME_CORRECT(new);
  return new;
}

/*
 * -maxdepth/-mindepth n functions --
 *
 *        Does the same as -prune if the level of the current file is
 *        greater/less than the specified maximum/minimum depth.
 *
 *        Note that -maxdepth and -mindepth are handled specially in
 *        find_execute() so their f_* functions are set to f_always_true().
 */
PLAN *c_mXXdepth(OPTION *option, char ***argvp) {
  char *dstr;
  PLAN *new;

  dstr = nextarg(option, argvp);
  if (dstr[0] == '-') /* all other errors handled by find_parsenum() */
    errx(1, "%s: %s: value must be positive", option->name, dstr);

  new = palloc(option);
  if (option->flags & F_MAXDEPTH)
    maxdepth = find_parsenum(new, option->name, dstr, NULL);
  else
    mindepth = find_parsenum(new, option->name, dstr, NULL);
  return new;
}

PLAN *c_acl(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_NOSTAT;
  return (palloc(option));
}

/*
 * -delete functions --
 *
 *	True always.  Makes its best shot and continues on regardless.
 */
int f_delete(PLAN *plan __unused, FTSENT *entry) {
  /* ignore these from fts */
  if (strcmp(entry->fts_accpath, ".") == 0 ||
      strcmp(entry->fts_accpath, "..") == 0)
    return 1;

  /* sanity check */
  if (isdepth == 0 ||            /* depth off */
      (ftsoptions & FTS_NOSTAT)) /* not stat()ing */
    errx(1, "-delete: insecure options got turned on");

  if (!(ftsoptions & FTS_PHYSICAL) || /* physical off */
      (ftsoptions & FTS_LOGICAL))     /* or finally, logical on */
    errx(1, "-delete: forbidden when symlinks are followed");

  /* Potentially unsafe - do not accept relative paths whatsoever */
  if (entry->fts_level > FTS_ROOTLEVEL &&
      strchr(entry->fts_accpath, '/') != NULL)
    errx(1, "-delete: %s: relative path potentially not safe",
         entry->fts_accpath);

#if HAVE_STRUCT_STAT_ST_FLAGS
  /* Turn off user immutable bits if running as root */
  if ((entry->fts_statp->st_flags & (UF_APPEND | UF_IMMUTABLE)) &&
      !(entry->fts_statp->st_flags & (SF_APPEND | SF_IMMUTABLE)) &&
      geteuid() == 0)
    lchflags(entry->fts_accpath,
             entry->fts_statp->st_flags &= ~(UF_APPEND | UF_IMMUTABLE));
#endif

  /* rmdir directories, unlink everything else */
  if (S_ISDIR(entry->fts_statp->st_mode)) {
    if (rmdir(entry->fts_accpath) < 0 && errno != ENOTEMPTY)
      warn("-delete: rmdir(%s)", entry->fts_path);
  } else {
    if (unlink(entry->fts_accpath) < 0)
      warn("-delete: unlink(%s)", entry->fts_path);
  }

  /* "succeed" */
  return 1;
}

PLAN *c_delete(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_NOSTAT; /* no optimise */
  isoutput = 1;              /* possible output */
  isdepth = 1;               /* -depth implied */

  /*
   * Try to avoid the confusing error message about relative paths
   * being potentially not safe.
   */
  if (ftsoptions & FTS_NOCHDIR)
    errx(1, "%s: forbidden when the current directory cannot be opened",
         "-delete");

  return palloc(option);
}

/*
 * always_true --
 *
 *	Always true, used for -maxdepth, -mindepth, -xdev, -follow, and -true
 */
int f_always_true(PLAN *plan __unused, FTSENT *entry __unused) { return 1; }

/*
 * -depth functions --
 *
 *	With argument: True if the file is at level n.
 *	Without argument: Always true, causes descent of the directory hierarchy
 *	to be done so that all entries in a directory are acted on before the
 *	directory itself.
 */
int f_depth(PLAN *plan, FTSENT *entry) {
  if (plan->flags & F_DEPTH)
    COMPARE(entry->fts_level, plan->d_data);
  else
    return 1;
}

PLAN *c_depth(OPTION *option, char ***argvp) {
  PLAN *new;
  char *str;

  new = palloc(option);

  str = **argvp;
  if (str && !(new->flags &F_DEPTH)) {
    /* skip leading + or - */
    if (*str == '+' || *str == '-') str++;
    /* skip sign */
    if (*str == '+' || *str == '-') str++;
    if (isdigit(*str)) new->flags |= F_DEPTH;
  }

  if (new->flags & F_DEPTH) { /* -depth n */
    char *ndepth;

    ndepth = nextarg(option, argvp);
    new->d_data = find_parsenum(new, option->name, ndepth, NULL);
  } else { /* -d */
    isdepth = 1;
  }

  return new;
}

/*
 * -empty functions --
 *
 *	True if the file or directory is empty
 */
int f_empty(PLAN *plan __unused, FTSENT *entry) {
  if (S_ISREG(entry->fts_statp->st_mode) && entry->fts_statp->st_size == 0)
    return 1;
  if (S_ISDIR(entry->fts_statp->st_mode)) {
    struct dirent *dp;
    int empty;
    DIR *dir;

    empty = 1;
    dir = opendir(entry->fts_accpath);
    if (dir == NULL) return 0;
    for (dp = readdir(dir); dp; dp = readdir(dir))
      if (dp->d_name[0] != '.' ||
          (dp->d_name[1] != '\0' &&
           (dp->d_name[1] != '.' || dp->d_name[2] != '\0'))) {
        empty = 0;
        break;
      }
    closedir(dir);
    return empty;
  }
  return 0;
}

PLAN *c_empty(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_NOSTAT;

  return palloc(option);
}

/*
 * [-exec | -execdir | -ok] utility [arg ... ] ; functions --
 *
 *	True if the executed utility returns a zero value as exit status.
 *	The end of the primary expression is delimited by a semicolon.  If
 *	"{}" occurs anywhere, it gets replaced by the current pathname,
 *	or, in the case of -execdir, the current basename (filename
 *	without leading directory prefix). For -exec and -ok,
 *	the current directory for the execution of utility is the same as
 *	the current directory when the find utility was started, whereas
 *	for -execdir, it is the directory the file resides in.
 *
 *	The primary -ok differs from -exec in that it requests affirmation
 *	of the user before executing the utility.
 */
int f_exec(PLAN *plan, FTSENT *entry) {
  int cnt;
  pid_t pid;
  int status;
  char *file;

  if (entry == NULL && plan->flags & F_EXECPLUS) {
    if (plan->e_ppos == plan->e_pbnum) return (1);
    plan->e_argv[plan->e_ppos] = NULL;
    goto doexec;
  }

  /* XXX - if file/dir ends in '/' this will not work -- can it? */
  if ((plan->flags & F_EXECDIR) && (file = strrchr(entry->fts_path, '/')))
    file++;
  else
    file = entry->fts_path;

  if (plan->flags & F_EXECPLUS) {
    if ((plan->e_argv[plan->e_ppos] = strdup(file)) == NULL) err(1, NULL);
    plan->e_len[plan->e_ppos] = strlen(file);
    plan->e_psize += plan->e_len[plan->e_ppos];
    if (++plan->e_ppos < plan->e_pnummax && plan->e_psize < plan->e_psizemax)
      return (1);
    plan->e_argv[plan->e_ppos] = NULL;
  } else {
    for (cnt = 0; plan->e_argv[cnt]; ++cnt)
      if (plan->e_len[cnt])
        brace_subst(plan->e_orig[cnt], &plan->e_argv[cnt], file,
                    plan->e_len[cnt]);
  }

doexec:
  if ((plan->flags & F_NEEDOK) && !queryuser(plan->e_argv)) return 0;

  /* make sure find output is interspersed correctly with subprocesses */
  fflush(stdout);
  fflush(stderr);

  switch (pid = fork()) {
    case -1:
      err(1, "fork");
      /* NOTREACHED */
    case 0:
      /* change dir back from where we started */
      if (!(plan->flags & F_EXECDIR) && !(ftsoptions & FTS_NOCHDIR) &&
          fchdir(dotfd)) {
        warn("chdir");
        _exit(1);
      }
      execvp(plan->e_argv[0], plan->e_argv);
      warn("%s", plan->e_argv[0]);
      _exit(1);
  }
  if (plan->flags & F_EXECPLUS) {
    while (--plan->e_ppos >= plan->e_pbnum) free(plan->e_argv[plan->e_ppos]);
    plan->e_ppos = plan->e_pbnum;
    plan->e_psize = plan->e_pbsize;
  }
  pid = waitpid(pid, &status, 0);
  if (pid != -1 && WIFEXITED(status) && !WEXITSTATUS(status)) return (1);
  if (plan->flags & F_EXECPLUS) {
    exitstatus = 1;
    return (1);
  }
  return (0);
}

/*
 * c_exec, c_execdir, c_ok --
 *	build three parallel arrays, one with pointers to the strings passed
 *	on the command line, one with (possibly duplicated) pointers to the
 *	argv array, and one with integer values that are lengths of the
 *	strings, but also flags meaning that the string has to be massaged.
 */
PLAN *c_exec(OPTION *option, char ***argvp) {
  PLAN *new; /* node returned */
  long argmax;
  int cnt, i;
  char **argv, **ap, **ep, *p;

  /* This would defeat -execdir's intended security. */
  if (option->flags & F_EXECDIR && ftsoptions & FTS_NOCHDIR)
    errx(1, "%s: forbidden when the current directory cannot be opened",
         "-execdir");

  /* XXX - was in c_execdir, but seems unnecessary!?
  ftsoptions &= ~FTS_NOSTAT;
  */
  isoutput = 1;

  /* XXX - this is a change from the previous coding */
  new = palloc(option);

  for (ap = argv = *argvp;; ++ap) {
    if (!*ap) errx(1, "%s: no terminating \";\" or \"+\"", option->name);
    if (**ap == ';') break;
    if (**ap == '+' && ap != argv && strcmp(*(ap - 1), "{}") == 0) {
      new->flags |= F_EXECPLUS;
      break;
    }
  }

  if (ap == argv) errx(1, "%s: no command specified", option->name);

  cnt = ap - *argvp + 1;
  if (new->flags & F_EXECPLUS) {
    new->e_ppos = new->e_pbnum = cnt - 2;
    if ((argmax = sysconf(_SC_ARG_MAX)) == -1) {
      warn("sysconf(_SC_ARG_MAX)");
      argmax = _POSIX_ARG_MAX;
    }
    argmax -= 1024;
    for (ep = environ; *ep != NULL; ep++)
      argmax -= strlen(*ep) + 1 + sizeof(*ep);
    argmax -= 1 + sizeof(*ep);
    /*
     * Ensure that -execdir ... {} + does not mix files
     * from different directories in one invocation.
     * Files from the same directory should be handled
     * in one invocation but there is no code for it.
     */
    new->e_pnummax = new->flags &F_EXECDIR ? 1 : argmax / 16;
    argmax -= sizeof(char *) * new->e_pnummax;
    if (argmax <= 0) errx(1, "no space for arguments");
    new->e_psizemax = argmax;
    new->e_pbsize = 0;
    cnt += new->e_pnummax + 1;
    new->e_next = lastexecplus;
    lastexecplus = new;
  }
  if ((new->e_argv = malloc(cnt * sizeof(char *))) == NULL) err(1, NULL);
  if ((new->e_orig = malloc(cnt * sizeof(char *))) == NULL) err(1, NULL);
  if ((new->e_len = malloc(cnt * sizeof(int))) == NULL) err(1, NULL);

  for (argv = *argvp, cnt = 0; argv < ap; ++argv, ++cnt) {
    new->e_orig[cnt] = *argv;
    if (new->flags & F_EXECPLUS) new->e_pbsize += strlen(*argv) + 1;
    for (p = *argv; *p; ++p)
      if (!(new->flags &F_EXECPLUS) && p[0] == '{' && p[1] == '}') {
        if ((new->e_argv[cnt] = malloc(MAXPATHLEN)) == NULL) err(1, NULL);
        new->e_len[cnt] = MAXPATHLEN;
        break;
      }
    if (!*p) {
      new->e_argv[cnt] = *argv;
      new->e_len[cnt] = 0;
    }
  }
  if (new->flags & F_EXECPLUS) {
    new->e_psize = new->e_pbsize;
    cnt--;
    for (i = 0; i < new->e_pnummax; i++) {
      new->e_argv[cnt] = NULL;
      new->e_len[cnt] = 0;
      cnt++;
    }
    argv = ap;
    goto done;
  }
  new->e_argv[cnt] = new->e_orig[cnt] = NULL;

done:
  *argvp = argv + 1;
  return new;
}

/* Finish any pending -exec ... {} + functions. */
void finish_execplus(void) {
  PLAN *p;

  p = lastexecplus;
  while (p != NULL) {
    (p->execute)(p, NULL);
    p = p->e_next;
  }
}

#if HAVE_STRUCT_STAT_ST_FLAGS
int f_flags(PLAN *plan, FTSENT *entry) {
  u_long flags;

  flags = entry->fts_statp->st_flags;
  if (plan->flags & F_ATLEAST)
    return (flags | plan->fl_flags) == flags && !(flags & plan->fl_notflags);
  else if (plan->flags & F_ANY)
    return (flags & plan->fl_flags) || (flags | plan->fl_notflags) != flags;
  else
    return flags == plan->fl_flags && !(plan->fl_flags & plan->fl_notflags);
}

PLAN *c_flags(OPTION *option, char ***argvp) {
  char *flags_str;
  PLAN *new;
  u_long flags, notflags;

  flags_str = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);

  if (*flags_str == '-') {
    new->flags |= F_ATLEAST;
    flags_str++;
  } else if (*flags_str == '+') {
    new->flags |= F_ANY;
    flags_str++;
  }
  if (strtofflags(&flags_str, &flags, &notflags) == 1)
    errx(1, "%s: %s: illegal flags string", option->name, flags_str);

  new->fl_flags = flags;
  new->fl_notflags = notflags;
  return new;
}
#endif

/*
 * -follow functions --
 *
 *	Always true, causes symbolic links to be followed on a global
 *	basis.
 */
PLAN *c_follow(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_PHYSICAL;
  ftsoptions |= FTS_LOGICAL;

  return palloc(option);
}

#if HAVE_STRUCT_STATFS_F_FSTYPENAME
/*
 * -fstype functions --
 *
 *	True if the file is of a certain type.
 */
int f_fstype(PLAN *plan, FTSENT *entry) {
  static dev_t curdev; /* need a guaranteed illegal dev value */
  static int first = 1;
  struct statfs sb;
  static int val_flags;
  static char fstype[sizeof(sb.f_fstypename)];
  char *p, save[2] = {0, 0};

  if ((plan->flags & F_MTMASK) == F_MTUNKNOWN) return 0;

  /* Only check when we cross mount point. */
  if (first || curdev != entry->fts_statp->st_dev) {
    curdev = entry->fts_statp->st_dev;

    /*
     * Statfs follows symlinks; find wants the link's filesystem,
     * not where it points.
     */
    if (entry->fts_info == FTS_SL || entry->fts_info == FTS_SLNONE) {
      if ((p = strrchr(entry->fts_accpath, '/')) != NULL)
        ++p;
      else
        p = entry->fts_accpath;
      save[0] = p[0];
      p[0] = '.';
      save[1] = p[1];
      p[1] = '\0';
    } else
      p = NULL;

    if (statfs(entry->fts_accpath, &sb)) {
      if (!ignore_readdir_race || errno != ENOENT) {
        warn("statfs: %s", entry->fts_accpath);
        exitstatus = 1;
      }
      return 0;
    }

    if (p) {
      p[0] = save[0];
      p[1] = save[1];
    }

    first = 0;

    /*
     * Further tests may need both of these values, so
     * always copy both of them.
     */
    val_flags = sb.f_flags;
    strlcpy(fstype, sb.f_fstypename, sizeof(fstype));
  }
  switch (plan->flags & F_MTMASK) {
    case F_MTFLAG:
      return val_flags & plan->mt_data;
    case F_MTTYPE:
      return (strncmp(fstype, plan->c_data, sizeof(fstype)) == 0);
    default:
      abort();
  }
}

PLAN *c_fstype(OPTION *option, char ***argvp) {
  char *fsname;
  PLAN *new;

  fsname = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  switch (*fsname) {
    case 'l':
      if (!strcmp(fsname, "local")) {
        new->flags |= F_MTFLAG;
        new->mt_data = MNT_LOCAL;
        return new;
      }
      break;
    case 'r':
      if (!strcmp(fsname, "rdonly")) {
        new->flags |= F_MTFLAG;
        new->mt_data = MNT_RDONLY;
        return new;
      }
      break;
  }

  new->flags |= F_MTTYPE;
  new->c_data = fsname;
  return new;
}
#endif

/*
 * -group gname functions --
 *
 *	True if the file belongs to the group gname.  If gname is numeric and
 *	an equivalent of the getgrnam() function does not return a valid group
 *	name, gname is taken as a group ID.
 */
int f_group(PLAN *plan, FTSENT *entry) {
  COMPARE(entry->fts_statp->st_gid, plan->g_data);
}

PLAN *c_group(OPTION *option, char ***argvp) {
  char *gname;
  PLAN *new;
  struct group *g;
  gid_t gid;

  gname = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  g = getgrnam(gname);
  if (g == NULL) {
    char *cp = gname;
    if (gname[0] == '-' || gname[0] == '+') gname++;
    gid = atoi(gname);
    if (gid == 0 && gname[0] != '0')
      errx(1, "%s: %s: no such group", option->name, gname);
    gid = find_parsenum(new, option->name, cp, NULL);
  } else
    gid = g->gr_gid;

  new->g_data = gid;
  return new;
}

/*
 * -ignore_readdir_race functions --
 *
 *	Always true. Ignore errors which occur if a file or a directory
 *	in a starting point gets deleted between reading the name and calling
 *	stat on it while find is traversing the starting point.
 */

PLAN *c_ignore_readdir_race(OPTION *option, char ***argvp __unused) {
  if (strcmp(option->name, "-ignore_readdir_race") == 0)
    ignore_readdir_race = 1;
  else
    ignore_readdir_race = 0;

  return palloc(option);
}

/*
 * -inum n functions --
 *
 *	True if the file has inode # n.
 */
int f_inum(PLAN *plan, FTSENT *entry) {
  COMPARE(entry->fts_statp->st_ino, plan->i_data);
}

PLAN *c_inum(OPTION *option, char ***argvp) {
  char *inum_str;
  PLAN *new;

  inum_str = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  new->i_data = find_parsenum(new, option->name, inum_str, NULL);
  return new;
}

/*
 * -samefile FN
 *
 *	True if the file has the same inode (eg hard link) FN
 */

/* f_samefile is just f_inum */
PLAN *c_samefile(OPTION *option, char ***argvp) {
  char *fn;
  PLAN *new;
  struct stat sb;
  int error;

  fn = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  if (ftsoptions & FTS_PHYSICAL)
    error = lstat(fn, &sb);
  else
    error = stat(fn, &sb);
  if (error != 0) err(1, "%s", fn);
  new->i_data = sb.st_ino;
  return new;
}

/*
 * -links n functions --
 *
 *	True if the file has n links.
 */
int f_links(PLAN *plan, FTSENT *entry) {
  COMPARE(entry->fts_statp->st_nlink, plan->l_data);
}

PLAN *c_links(OPTION *option, char ***argvp) {
  char *nlinks;
  PLAN *new;

  nlinks = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  new->l_data = (nlink_t)find_parsenum(new, option->name, nlinks, NULL);
  return new;
}

/*
 * -ls functions --
 *
 *	Always true - prints the current entry to stdout in "ls" format.
 */
int f_ls(PLAN *plan __unused, FTSENT *entry) {
  printlong(entry->fts_path, entry->fts_accpath, entry->fts_statp);
  return 1;
}

PLAN *c_ls(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_NOSTAT;
  isoutput = 1;

  return palloc(option);
}

/*
 * -name functions --
 *
 *	True if the basename of the filename being examined
 *	matches pattern using Pattern Matching Notation S3.14
 */
int f_name(PLAN *plan, FTSENT *entry) {
  char fn[PATH_MAX];
  const char *name;
  ssize_t len;

  if (plan->flags & F_LINK) {
    /*
     * The below test both avoids obviously useless readlink()
     * calls and ensures that symlinks with existent target do
     * not match if symlinks are being followed.
     * Assumption: fts will stat all symlinks that are to be
     * followed and will return the stat information.
     */
    if (entry->fts_info != FTS_NSOK && entry->fts_info != FTS_SL &&
        entry->fts_info != FTS_SLNONE)
      return 0;
    len = readlink(entry->fts_accpath, fn, sizeof(fn) - 1);
    if (len == -1) return 0;
    fn[len] = '\0';
    name = fn;
  } else
    name = entry->fts_name;
  return !fnmatch(plan->c_data, name,
                  plan->flags & F_IGNCASE ? FNM_CASEFOLD : 0);
}

PLAN *c_name(OPTION *option, char ***argvp) {
  char *pattern;
  PLAN *new;

  pattern = nextarg(option, argvp);
  new = palloc(option);
  new->c_data = pattern;
  return new;
}

/*
 * -newer file functions --
 *
 *	True if the current file has been modified more recently
 *	then the modification time of the file named by the pathname
 *	file.
 */
int f_newer(PLAN *plan, FTSENT *entry) {
  struct timespec ft;

  if (plan->flags & F_TIME_C) ft = entry->fts_statp->st_ctim;
#if HAVE_STRUCT_STAT_ST_BIRTHTIME
  else if (plan->flags & F_TIME_A)
    ft = entry->fts_statp->st_atim;
  else if (plan->flags & F_TIME_B)
    ft = entry->fts_statp->st_birthtim;
#endif
  else
    ft = entry->fts_statp->st_mtim;
  return (
      ft.tv_sec > plan->t_data.tv_sec ||
      (ft.tv_sec == plan->t_data.tv_sec && ft.tv_nsec > plan->t_data.tv_nsec));
}

PLAN *c_newer(OPTION *option, char ***argvp) {
  char *fn_or_tspec;
  PLAN *new;
  struct stat sb;
  int error;

  fn_or_tspec = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  /* compare against what */
  if (option->flags & F_TIME2_T) {
    new->t_data.tv_sec = get_date(fn_or_tspec);
    if (new->t_data.tv_sec == (time_t)-1)
      errx(1, "Can't parse date/time: %s", fn_or_tspec);
    /* Use the seconds only in the comparison. */
    new->t_data.tv_nsec = 999999999;
  } else {
    if (ftsoptions & FTS_PHYSICAL)
      error = lstat(fn_or_tspec, &sb);
    else
      error = stat(fn_or_tspec, &sb);
    if (error != 0) err(1, "%s", fn_or_tspec);
    if (option->flags & F_TIME2_C)
      new->t_data = sb.st_ctim;
    else if (option->flags & F_TIME2_A)
      new->t_data = sb.st_atim;
#if HAVE_STRUCT_STAT_ST_BIRTHTIME
    else if (option->flags & F_TIME2_B)
      new->t_data = sb.st_birthtim;
#endif
    else
      new->t_data = sb.st_mtim;
  }
  return new;
}

/*
 * -nogroup functions --
 *
 *	True if file belongs to a user ID for which the equivalent
 *	of the getgrnam() 9.2.1 [POSIX.1] function returns NULL.
 */
int f_nogroup(PLAN *plan __unused, FTSENT *entry) {
  return group_from_gid(entry->fts_statp->st_gid, 1) == NULL;
}

PLAN *c_nogroup(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_NOSTAT;

  return palloc(option);
}

/*
 * -nouser functions --
 *
 *	True if file belongs to a user ID for which the equivalent
 *	of the getpwuid() 9.2.2 [POSIX.1] function returns NULL.
 */
int f_nouser(PLAN *plan __unused, FTSENT *entry) {
  return user_from_uid(entry->fts_statp->st_uid, 1) == NULL;
}

PLAN *c_nouser(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_NOSTAT;

  return palloc(option);
}

/*
 * -path functions --
 *
 *	True if the path of the filename being examined
 *	matches pattern using Pattern Matching Notation S3.14
 */
int f_path(PLAN *plan, FTSENT *entry) {
  return !fnmatch(plan->c_data, entry->fts_path,
                  plan->flags & F_IGNCASE ? FNM_CASEFOLD : 0);
}

/* c_path is the same as c_name */

/*
 * -perm functions --
 *
 *	The mode argument is used to represent file mode bits.  If it starts
 *	with a leading digit, it's treated as an octal mode, otherwise as a
 *	symbolic mode.
 */
int f_perm(PLAN *plan, FTSENT *entry) {
  mode_t mode;

  mode = entry->fts_statp->st_mode &
         (S_ISUID | S_ISGID | S_ISTXT | S_IRWXU | S_IRWXG | S_IRWXO);
  if (plan->flags & F_ATLEAST)
    return (plan->m_data | mode) == mode;
  else if (plan->flags & F_ANY)
    return (mode & plan->m_data);
  else
    return mode == plan->m_data;
  /* NOTREACHED */
}

PLAN *c_perm(OPTION *option, char ***argvp) {
  char *perm;
  PLAN *new;
  mode_t *set;

  perm = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);

  if (*perm == '-') {
    new->flags |= F_ATLEAST;
    ++perm;
  } else if (*perm == '+') {
    new->flags |= F_ANY;
    ++perm;
  }

  if ((set = setmode(perm)) == NULL)
    errx(1, "%s: %s: illegal mode string", option->name, perm);

  new->m_data = getmode(set, 0);
  free(set);
  return new;
}

/*
 * -print functions --
 *
 *	Always true, causes the current pathname to be written to
 *	standard output.
 */
int f_print(PLAN *plan __unused, FTSENT *entry) {
  (void)puts(entry->fts_path);
  return 1;
}

PLAN *c_print(OPTION *option, char ***argvp __unused) {
  isoutput = 1;

  return palloc(option);
}

/*
 * -print0 functions --
 *
 *	Always true, causes the current pathname to be written to
 *	standard output followed by a NUL character
 */
int f_print0(PLAN *plan __unused, FTSENT *entry) {
  fputs(entry->fts_path, stdout);
  fputc('\0', stdout);
  return 1;
}

/* c_print0 is the same as c_print */

/*
 * -prune functions --
 *
 *	Prune a portion of the hierarchy.
 */
int f_prune(PLAN *plan __unused, FTSENT *entry) {
  if (fts_set(tree, entry, FTS_SKIP)) err(1, "%s", entry->fts_path);
  return 1;
}

/* c_prune == c_simple */

/*
 * -regex functions --
 *
 *	True if the whole path of the file matches pattern using
 *	regular expression.
 */
int f_regex(PLAN *plan, FTSENT *entry) {
  char *str;
  int len;
  regex_t *pre;
  regmatch_t pmatch;
  int errcode;
  char errbuf[LINE_MAX];
  int matched;

  pre = plan->re_data;
  str = entry->fts_path;
  len = strlen(str);
  matched = 0;

  pmatch.rm_so = 0;
  pmatch.rm_eo = len;

  // TODO/NOTE: could be issues with null's.
  #define REG_STARTEND 0
  errcode = regexec(pre, str, 1, &pmatch, REG_STARTEND);

  if (errcode != 0 && errcode != REG_NOMATCH) {
    regerror(errcode, pre, errbuf, sizeof errbuf);
    errx(1, "%s: %s", plan->flags & F_IGNCASE ? "-iregex" : "-regex", errbuf);
  }

  if (errcode == 0 && pmatch.rm_so == 0 && pmatch.rm_eo == len) matched = 1;

  return matched;
}

PLAN *c_regex(OPTION *option, char ***argvp) {
  PLAN *new;
  char *pattern;
  regex_t *pre;
  int errcode;
  char errbuf[LINE_MAX];

  if ((pre = malloc(sizeof(regex_t))) == NULL) err(1, NULL);

  pattern = nextarg(option, argvp);

  if ((errcode = regcomp(
           pre, pattern,
           regexp_flags | (option->flags & F_IGNCASE ? REG_ICASE : 0))) != 0) {
    regerror(errcode, pre, errbuf, sizeof errbuf);
    errx(1, "%s: %s: %s", option->flags & F_IGNCASE ? "-iregex" : "-regex",
         pattern, errbuf);
  }

  new = palloc(option);
  new->re_data = pre;

  return new;
}

/* c_simple covers c_prune, c_openparen, c_closeparen, c_not, c_or, c_true,
 * c_false */

PLAN *c_simple(OPTION *option, char ***argvp __unused) {
  return palloc(option);
}

/*
 * -size n[c] functions --
 *
 *	True if the file size in bytes, divided by an implementation defined
 *	value and rounded up to the next integer, is n.  If n is followed by
 *      one of c k M G T P, the size is in bytes, kilobytes,
 *      megabytes, gigabytes, terabytes or petabytes respectively.
 */
#define FIND_SIZE 512
static int divsize = 1;

int f_size(PLAN *plan, FTSENT *entry) {
  off_t size;

  size = divsize ? (entry->fts_statp->st_size + FIND_SIZE - 1) / FIND_SIZE
                 : entry->fts_statp->st_size;
  COMPARE(size, plan->o_data);
}

PLAN *c_size(OPTION *option, char ***argvp) {
  char *size_str;
  PLAN *new;
  char endch;
  off_t scale;

  size_str = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  endch = 'c';
  new->o_data = find_parsenum(new, option->name, size_str, &endch);
  if (endch != '\0') {
    divsize = 0;

    switch (endch) {
      case 'c': /* characters */
        scale = 0x1LL;
        break;
      case 'k': /* kilobytes 1<<10 */
        scale = 0x400LL;
        break;
      case 'M': /* megabytes 1<<20 */
        scale = 0x100000LL;
        break;
      case 'G': /* gigabytes 1<<30 */
        scale = 0x40000000LL;
        break;
      case 'T': /* terabytes 1<<40 */
        scale = 0x10000000000LL;
        break;
      case 'P': /* petabytes 1<<50 */
        scale = 0x4000000000000LL;
        break;
      default:
        errx(1, "%s: %s: illegal trailing character", option->name, size_str);
        break;
    }
    if (new->o_data > QUAD_MAX / scale)
      errx(1, "%s: %s: value too large", option->name, size_str);
    new->o_data *= scale;
  }
  return new;
}

/*
 * -sparse functions --
 *
 *      Check if a file is sparse by finding if it occupies fewer blocks
 *      than we expect based on its size.
 */
int f_sparse(PLAN *plan __unused, FTSENT *entry) {
  off_t expected_blocks;

  expected_blocks = (entry->fts_statp->st_size + 511) / 512;
  return entry->fts_statp->st_blocks < expected_blocks;
}

PLAN *c_sparse(OPTION *option, char ***argvp __unused) {
  ftsoptions &= ~FTS_NOSTAT;

  return palloc(option);
}

/*
 * -type c functions --
 *
 *	True if the type of the file is c, where c is b, c, d, p, f or w
 *	for block special file, character special file, directory, FIFO,
 *	regular file or whiteout respectively.
 */
int f_type(PLAN *plan, FTSENT *entry) {
  if (plan->m_data == S_IFDIR)
    return (entry->fts_info == FTS_D || entry->fts_info == FTS_DC ||
            entry->fts_info == FTS_DNR || entry->fts_info == FTS_DOT ||
            entry->fts_info == FTS_DP);
  else
    return (entry->fts_statp->st_mode & S_IFMT) == plan->m_data;
}

PLAN *c_type(OPTION *option, char ***argvp) {
  char *typestring;
  PLAN *new;
  mode_t mask;

  typestring = nextarg(option, argvp);
  if (typestring[0] != 'd') ftsoptions &= ~FTS_NOSTAT;

  switch (typestring[0]) {
    case 'b':
      mask = S_IFBLK;
      break;
    case 'c':
      mask = S_IFCHR;
      break;
    case 'd':
      mask = S_IFDIR;
      break;
    case 'f':
      mask = S_IFREG;
      break;
    case 'l':
      mask = S_IFLNK;
      break;
    case 'p':
      mask = S_IFIFO;
      break;
    case 's':
      mask = S_IFSOCK;
      break;
#if defined(FTS_WHITEOUT) && defined(S_IFWHT)
    case 'w':
      mask = S_IFWHT;
      ftsoptions |= FTS_WHITEOUT;
      break;
#endif /* FTS_WHITEOUT */
    default:
      errx(1, "%s: %s: unknown type", option->name, typestring);
  }

  new = palloc(option);
  new->m_data = mask;
  return new;
}

/*
 * -user uname functions --
 *
 *	True if the file belongs to the user uname.  If uname is numeric and
 *	an equivalent of the getpwnam() S9.2.2 [POSIX.1] function does not
 *	return a valid user name, uname is taken as a user ID.
 */
int f_user(PLAN *plan, FTSENT *entry) {
  COMPARE(entry->fts_statp->st_uid, plan->u_data);
}

PLAN *c_user(OPTION *option, char ***argvp) {
  char *username;
  PLAN *new;
  struct passwd *p;
  uid_t uid;

  username = nextarg(option, argvp);
  ftsoptions &= ~FTS_NOSTAT;

  new = palloc(option);
  p = getpwnam(username);
  if (p == NULL) {
    char *cp = username;
    if (username[0] == '-' || username[0] == '+') username++;
    uid = atoi(username);
    if (uid == 0 && username[0] != '0')
      errx(1, "%s: %s: no such user", option->name, username);
    uid = find_parsenum(new, option->name, cp, NULL);
  } else
    uid = p->pw_uid;

  new->u_data = uid;
  return new;
}

/*
 * -xdev functions --
 *
 *	Always true, causes find not to descend past directories that have a
 *	different device ID (st_dev, see stat() S5.6.2 [POSIX.1])
 */
PLAN *c_xdev(OPTION *option, char ***argvp __unused) {
  ftsoptions |= FTS_XDEV;

  return palloc(option);
}

/*
 * ( expression ) functions --
 *
 *	True if expression is true.
 */
int f_expr(PLAN *plan, FTSENT *entry) {
  PLAN *p;
  int state = 0;

  for (p = plan->p_data[0]; p && (state = (p->execute)(p, entry)); p = p->next)
    ;
  return state;
}

/*
 * f_openparen and f_closeparen nodes are temporary place markers.  They are
 * eliminated during phase 2 of find_formplan() --- the '(' node is converted
 * to a f_expr node containing the expression and the ')' node is discarded.
 * The functions themselves are only used as constants.
 */

int f_openparen(PLAN *plan __unused, FTSENT *entry __unused) { abort(); }

int f_closeparen(PLAN *plan __unused, FTSENT *entry __unused) { abort(); }

/* c_openparen == c_simple */
/* c_closeparen == c_simple */

/*
 * AND operator. Since AND is implicit, no node is allocated.
 */
PLAN *c_and(OPTION *option __unused, char ***argvp __unused) { return NULL; }

/*
 * ! expression functions --
 *
 *	Negation of a primary; the unary NOT operator.
 */
int f_not(PLAN *plan, FTSENT *entry) {
  PLAN *p;
  int state = 0;

  for (p = plan->p_data[0]; p && (state = (p->execute)(p, entry)); p = p->next)
    ;
  return !state;
}

/* c_not == c_simple */

/*
 * expression -o expression functions --
 *
 *	Alternation of primaries; the OR operator.  The second expression is
 * not evaluated if the first expression is true.
 */
int f_or(PLAN *plan, FTSENT *entry) {
  PLAN *p;
  int state = 0;

  for (p = plan->p_data[0]; p && (state = (p->execute)(p, entry)); p = p->next)
    ;

  if (state) return 1;

  for (p = plan->p_data[1]; p && (state = (p->execute)(p, entry)); p = p->next)
    ;
  return state;
}

/* c_or == c_simple */

/*
 * -false
 *
 *	Always false.
 */
int f_false(PLAN *plan __unused, FTSENT *entry __unused) { return 0; }

/* c_false == c_simple */

/*
 * -quit
 *
 *	Exits the program
 */
int f_quit(PLAN *plan __unused, FTSENT *entry __unused) {
  finish_execplus();
  exit(exitstatus);
}

/* c_quit == c_simple */
